The loan is set to $200,000, the interest rate is 4% fixed, term 30 years.

Change the interest rate to 3.5% and make this a variable rate with 7 years fixed interest. Variable rate ARM loans usually have lower interest rates, but after 7 years - assume the interest rate goes up by .25%

3) If you pay an extra $300 a month and pay $20,000 additional payment on the 85th month (or right after 7 years) .. a) how much interest will you save, b) what date will the entire loan get paid , c) how much taxes will you save, d) what is the loan balance on year 12 ? e) how much was the total payment of the entire loan, f) how much was the total interest payment

4)If you pay an extra $350 a month and pay $35,000 additional payment on the 85th month (or right after 7 years) .. a) how much interest will you save, b) what date will the entire loan get paid , c) how much taxes will you save, d) what is the loan balance on year 18 ? e) how much was the total payment of the entire loan, f) how much was the total interest payment